Hitherto, there is a lamp system using a straight tube type lamp based on general Japan Lighting Manufacturers Association standard JEL801 “straight tube type LED lamp system with L-shaped cap” and a socket for mounting the straight tube type lamp.
As disclosed in, for example, PTL 1, in the straight tube type lamp, caps are arranged at both ends in a lamp longitudinal direction, a pair of L-shaped lamp pins whose tips protrude in outside directions intersecting the lamp longitudinal direction are protrudingly provided on an end face of the cap at one end, and one non-feeding side pin is protrudingly provided on an end face of the cap at the other end.
On the other hand, the straight tube type lamp mounted on a corresponding socket can expand and contract in the lamp longitudinal direction according to the temperature. Thus, in the straight tube type lamp of PTL 1, the non-feeding side pin can move in the lamp longitudinal direction with respective to a terminal to support the non-feeding side pin, and even when the lamp pin at the one end side is mounted on the socket, the non-feeding side pin at the other end side moves in the lamp longitudinal direction and can absorb the expansion and contraction of the lamp.